1. Field of the Invention
The present invention relates to a powder coating composition. More specifically, it relates to a powder coating composition having an improved stain resistance (or dirt retention) and solvent resistance.
2. Description of the Related Art
Polyester powder coating compositions are widely applied to, for example, refrigerators, washing machines, and electric ovens since these polyester powder coating compositions have excellent corrosion resistance, weathering resistance, and flexibility. However, resistance against stains caused by, for example, oily ink (or magic markers), mustard, and lipstick is strongly required, in addition to the above-mentioned characteristics, and when used as a coating on household applicances such as refrigerators and washing machines, the polyester powder coating compositions have a disadvantage in that their stain resistance is extremely low when compared to that of acrylic powder coating compositions and epoxy powder coating compositions. Various attempts have been made to improve the poor stain resistance of the polyester coating compositions. For example, it has been proposed that the composition of polyester resins be modified so that the polyester resins are not dissolved in solvents. However, these proposals are not satisfactory when put to practical use, in that not only is the stain resistance insufficiently improved, but also the visual appearance of the resultant coating becomes remarkably poor.